Frame for a mask



FIG. 1 is a front perspective view of a frame for a mask according to an embodiment of our design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a is a right side view thereof with the left side view being a mirror image thereof.

Where included, broken lines showing environment or structure are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a frame for a mask, as shown and described. 